Please try to answer every question and show work. 1) Calculate G° for the autoi
ID: 1063917 • Letter: P
Question
Please try to answer every question and show work.
1) Calculate G° for the autoionization of water at 25 °C. Kw = 1.0 × 10-14
2) Consider the reaction: NH3 (g) + HCl (g) NH4Cl (s) Given the following table of thermodynamic data, Substance Hf° (kJ/mol) S° (J/mol K) NH3 (g) -46.19 192.5 HCl (g) -92.30 186.69 NH4Cl (s) -314.4 94.6 determine the temperature (in °C) above which the reaction is nonspontaneous.
3) A reaction that is not spontaneous at low temperature can become spontaneous at high temperature if H is ________ and S is ________.
4) Phosphorous and chlorine gases combine to produce phosphorous trichloride: P2 (g) + 3Cl2 (g) 2PCl3 (g) G° at 298 K for this reaction is -642.9 kJ/mol. The value of G at 298 K for a reaction mixture that consists of 1.9 atm P2, 1.6 atm Cl2, and 0.65 atm PCl3 is ________.
5) The value of G° at 25 °C for the following reaction: C2H4 (g) + H2 (g) C2H6 (g) is ________ kJ/mol. At 298 K, H° for this reaction is -137.5 kJ/mol, and S° is +120.5 J/K.
Explanation / Answer
1. We know that
G°=-2.303RTlogKw
G°=-2.303×8.314×298×log(10-14) J
G°=79881.7 J
G°=79.88 KJ